This invention relates to electron field emission devices and more particularly, but not exclusively, to display arrangements including such devices.
Much cathode ray tube display technology is now being superseded by both passive and more recently active matrix liquid crystal display technology. This flat panel technology has many advantages over cathode ray tube (CRT) including lighter weight compact shape and lower cost. However, such displays have a number of obvious disadvantages, notably the poor viewing angle and their intrinsically non emissive nature. Although active matrix liquid crystal technology has been developed to overcome the latter deficiency it is at the expense of device complexity and the resulting reduced manufacturing yield leads to high cost, particularly as the technology is scaled up to larger screen sizes. In addition, because such devices involve the shuttering of a back light they are intrinsically inefficient.
A competitive technology based on arrays of field emitter cold cathodes has been developed which provides all the advantages of the flat, liquid crystal display but with the brightness and viewing angle of the cathode ray tube. This novel technology is, however, yet to come into production because the lack of low voltage phosphors and the limited lifetimes of field emitter tips.